opera email labeling a sent message

My sent messages appear in the "sent" folder of the email account and also in the "sent" folder of "all messages". I have tried "labeling" a "sent" message and it does not work. The label gets "checked" but the message does not show up when I click on the label. Is it possible to "label" a "sent" message?

Again I have to thank you. How in the heck do you know all this stuff. I would never figure it out. Thanks again for taking time to help me. I am really liking OperaMail but I have to say it has been a struggle because of the philosophical difference between Opera and other email programs.

New problem. When I open OperaMail, it comes to full screen. But I like to have it in a certain place on the screen. So I reduce the size and move it to exactly where I want it. But the next time I open OperaMail, it is back to full screen. Is there a way to prevent this?